scholarly journals Anagrus breviphragmaSoyka Short Distance Search Stimuli

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Elisabetta Chiappini ◽  
Alessia Berzolla ◽  
Annalisa Oppo
Keyword(s):  
Short Distance ◽  
Leaf Surface ◽  
Polar Solvents ◽  
Starting Time ◽  
Physical Cues ◽  
Physical Stimuli ◽  
Cicadella Viridis

Anagrus breviphragmaSoyka (Hymenoptera: Mymaridae) successfully parasitises eggs ofCicadella viridis(L.) (Homoptera: Cicadellidae), embedded in vegetal tissues, suggesting the idea of possible chemical and physical cues, revealing the eggs presence. In this research, three treatments were considered in order to establish which types of cue are involved: eggs extracted from leaf, used as a control, eggs extracted from leaf and cleaned in water and ethanol, used to evaluate the presence of chemicals soluble in polar solvents, and eggs extracted from leaf and covered with Parafilm (M), used to avoid physical stimuli due to the bump on the leaf surface. The results show that eggs covered with Parafilm present a higher number of parasitised eggs and a lower probing starting time with respect to eggs washed with polar solvents or eggs extracted and untreated, both when the treatments were singly tested or when offered in sequence, independently of the treatment position. These results suggest that the exploited stimuli are not physical due to the bump but chemicals that can spread in the Parafilm, circulating the signal on the whole surface, and that the stimuli that elicit probing and oviposition are not subjected to learning.

Endophytic relationship between an entomopathogenic fungus Beauveria bassiana and corn (zea mays)

1995 ◽  
Vol 53 ◽  
pp. 988-989
Author(s):  
Bruce L. Wagner ◽  
Leslie C. Lewis
Keyword(s):  
Zea Mays ◽  
Beauveria Bassiana ◽  
Ostrinia Nubilalis ◽  
Entomopathogenic Fungus ◽  
Short Distance ◽  
Germ Tube ◽  
Leaf Surface ◽  
Insect Host ◽  
Lepidoptera Pyralidae ◽  
Fungus Beauveria Bassiana

Fungi are known to colonize plants, usually as phytopathogens or symbionts. This is the first report of the entomopathogenic fungus, Beauveria bassiana (Balsamo) Vuillemin (Deuteromycotina: Hyphomycetes) penetrating and colonizing a plant in a manner similar to when it invades a typical insect host Ostrinia nubilalis Hübner (Lepidoptera: Pyralidae). Electron microscopy was used to document this fungus penetrating the leaves of corn (Zea mays) and establishing an endophytic relationship within the plant.Several studies have shown B. bassiana to adhere to insect cuticle and penetrate with or without forming appressorial penetration structures. Investigations have concluded that the young, germinating hyphae may produce sequentially a proteinase followed by chitinase to dissolve the cuticular envelope of target insects. Within three days after inoculation, viable B. bassiana conidia germinated and formed vegetative mycelia which grew randomly over the corn leaf surface (Fig. 1). Often a germ tube is formed from a conidium and elongates only a short distance before terminating its growth and penetrating the leaf surface (Figs. 2 and 3).

SOOTY MOULD DISEASES OF SOME TREES FROM AURANGABAD DISTRICT, MAHARASHTRA (INDIA)

2017 ◽  
Vol 23 (2) ◽  
Author(s):  
NAVALSINGH J. TODAWAT
Keyword(s):  
Surface Area ◽  
Fungal Pathogens ◽  
Leaf Surface ◽  
Severity Of Disease ◽  
Sooty Mould ◽  
Leaf Surface Area

Sooty mould diseases of Tress from Aurangabad district were surveyed. During the survey of tress, 5 species were found infected by fungal pathogens causing sooty mould diseases. Disease is easily identifiable by the presence of a black, velvety growth covering the leaf surface area. The fungus produces mycelium which is superficial and dark grows on the flowers, leaf, stem and sometime on fruits also. The severity of disease depends on the honeydew secretions by insects. The diseases were found to be caused by 5 species of fungi viz. Capnodium anonae, C. ramosum, Capnodium sp., Meliola bangalorensis and Meliola ranganthii.

Leaf surface and endophytic fungi associated with onion leaves and their antagonistic activity against Alternaria porri.

2015 ◽  
Vol 67 (1) ◽  
pp. 1-22 ◽  
Author(s):  
Sobhy I. I. Abdel-Hafez ◽  
Kamal A. M. Abo-Elyousr ◽  
Ismail R. Abdel-Rahim
Keyword(s):  
Endophytic Fungi ◽  
Leaf Surface ◽  
Antagonistic Activity ◽  
Alternaria Porri

Tele-Substitution Reactions in the Synthesis of a Promising Class of Antimalarials

2020 ◽  
Author(s):  
Marat Korsik ◽  
Edwin Tse ◽  
David Smith ◽  
William Lewis ◽  
Peter J. Rutledge ◽  
...  
Keyword(s):  
Heterocyclic Ring ◽  
Ring System ◽  
Substitution Reactions ◽  
Laboratory Notebook ◽  
Polar Solvents ◽  
X Ray ◽  
X Ray Crystallography ◽  
The Core ◽  
Nmr Data

<p></p><p>We have discovered and studied a <i>tele</i>substitution reaction in a biologically important heterocyclic ring system. Conditions that favour the <i>tele</i>-substitution pathway were identified: the use of increased equivalents of the nucleophile or decreased equivalents of base, or the use of softer nucleophiles, less polar solvents and larger halogens on the electrophile. Using results from X-ray crystallography and isotope labelling experiments a mechanism for this unusual transformation is proposed. We focused on this triazolopyrazine as it is the core structure of the <i>in vivo </i>active anti-plasmodium compounds of Series 4 of the Open Source Malaria consortium.</p> <p> </p> <p>Archive of the electronic laboratory notebook with the description of all conducted experiments and raw NMR data could be accessed via following link <a href="https://ses.library.usyd.edu.au/handle/2123/21890">https://ses.library.usyd.edu.au/handle/2123/21890</a> . For navigation between entries of laboratory notebook please use file "Strings for compounds in the article.pdf" that works as a reference between article codes and notebook codes, also this file contain SMILES for these compounds. </p><br><p></p>

Stereospecific 1,3-H Transfer of Indenols Proceeds via Persistent Ion-Pairs Anchored By NH···Pi Interactions

2018 ◽  
Author(s):  
David Ascough ◽  
Fernanda Duarte ◽  
Robert Paton
Keyword(s):  
Computational Analysis ◽  
Ion Pairs ◽  
Ion Pair ◽  
Hydrogen Atom Transfer ◽  
Polar Solvents ◽  
Chirality Transfer ◽  
Activation Barriers ◽  
Sense And Avoid ◽  
Phase Dynamics ◽  
Pi Interactions

The base-catalyzed rearrangement of arylindenols is a rare example of a suprafacial [1,3]-hydrogen atom transfer. The mechanism has been proposed to proceed via sequential [1,5]-sigmatropic shifts, which occur in a selective sense and avoid an achiral intermediate. A computational analysis using quantum chemistry casts serious doubt on these suggestions: these pathways have enormous activation barriers and in constrast to what is observed experimentally, they overwhelmingly favor a racemic product. Instead we propose that a suprafacial [1,3]-prototopic shift occurs in a two-step deprotonation/reprotonation sequence. This mechanism is favored by 15 kcal mol<sup>-1</sup> over that previously proposed. Most importantly, this is also consistent with stereospecificity since reprotonation occurs rapidly on the same p-face. We have used explicitly-solvated molecular dynamics studies to study the persistence and condensed-phase dynamics of the intermediate ion-pair formed in this reaction. Chirality transfer is the result of a particularly resilient contact ion-pair, held together by electrostatic attraction and a critical NH···p interaction which ensures that this species has an appreciable lifetime even in polar solvents such as DMSO and MeOH.

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